Javafx: Update the SceneBuilder asynchronously, because it's a quite heavy operation.

plugins/javaFX/src/org/jetbrains/plugins/javaFX/sceneBuilder/SceneBuilderEditor.java

@@ -32,6 +32,7 @@ import java.beans.PropertyChangeListener;
 import java.io.File;
 import java.util.*;
 import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.stream.Collectors;
 
 /**
@@ -49,10 +50,10 @@ public class SceneBuilderEditor extends UserDataHolderBase implements FileEditor
   private final CardLayout myLayout = new CardLayout();
   private final JPanel myPanel = new JPanel(myLayout);
 
-  //private final JPanel myErrorPanel = new JPanel(new VerticalFlowLayout(VerticalFlowLayout.TOP, 10, 5, true, false));
   private final JPanel myErrorPanel = new JPanel(new BorderLayout());
   private final HyperlinkLabel myErrorLabel = new HyperlinkLabel();
   private JTextArea myErrorStack;
+  private final AtomicBoolean myIsUpdateStatePending = new AtomicBoolean();
 
   private final Document myDocument;
   private final ExternalChangeListener myChangeListener;
@@ -164,12 +165,18 @@ public class SceneBuilderEditor extends UserDataHolderBase implements FileEditor
   }
 
   private void updateState() {
-    addSceneBuilder();
+    if (myIsUpdateStatePending.compareAndSet(false, true)) {
+      removeSceneBuilder(); // remove immediately to avoid showing old contents for a moment
+
+      ApplicationManager.getApplication().invokeLater(() -> {
+        if (myIsUpdateStatePending.compareAndSet(true, false)) {
+          addSceneBuilder();
+        }
+      });
+    }
   }
 
   private void addSceneBuilder() {
-    removeSceneBuilder();
-
     try {
       FileDocumentManager.getInstance().saveDocument(myDocument);
 
@@ -188,11 +195,13 @@ public class SceneBuilderEditor extends UserDataHolderBase implements FileEditor
   private void removeSceneBuilder() {
     myChangeListener.stop();
 
-    if (mySceneBuilder != null) {
-      myPanel.remove(mySceneBuilder.getPanel());
-      mySceneBuilder.close();
-      mySceneBuilder = null;
-    }
+    UIUtil.invokeLaterIfNeeded(() -> {
+      if (mySceneBuilder != null) {
+        myPanel.remove(mySceneBuilder.getPanel());
+        mySceneBuilder.close();
+        mySceneBuilder = null;
+      }
+    });
   }
 
   @NotNull